计算 |1/3-1/2|+|1/4-1/3|+|1/5-1/4|+...+|1/2007-1/2006|.列式、
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计算 |1/3-1/2|+|1/4-1/3|+|1/5-1/4|+...+|1/2007-1/2006|.列式、
计算 |1/3-1/2|+|1/4-1/3|+|1/5-1/4|+...+|1/2007-1/2006|.
列式、
计算 |1/3-1/2|+|1/4-1/3|+|1/5-1/4|+...+|1/2007-1/2006|.列式、
原式=1/2-1/2007=2005/4014 直接这样写
|1/3-1/2|+|1/4-1/3|+|1/5-1/4|+...+|1/2007-1/2006|。
=(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+...+(1/2006-1/2007)
=1/2+(-1/3+1/3)(-1/4+1/4)(-1/5+1/5)+...(-1/2006+1/2006)(-1/2007+1/2007)
=1/2
10/51
|1/3-1/2|+|1/4-1/3|+|1/5-1/4|+...+|1/2007-1/2006=1/2+1/2007=2005/4014
1/2-1/2007=2005/4014
|1/3-1/2|+|1/4-1/3|+|1/5-1/4|+...+|1/2007-1/2006|。
=(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+...+(1/2006-1/2007)
=1/2-1/3+1/3-1/4+1/4+...-1/2006+1/2006-1/2007
=1/2-1/2007
=2005/4014
(1/3-1/2)<0 所以|1/3-1/2|=1/2-1/3
(1/4-1/3)<0 所以|1/4-1/3|=1/3-1/4
(1/5-1/4)<0 所以|1/5-1/4|=1/4-1/5
...
(1/2007-1/2006)>0 所以 |1/2007-1/2006|=1/2006-1-2007
那么原式就可以表示为
(1/2-1/3)+(...
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(1/3-1/2)<0 所以|1/3-1/2|=1/2-1/3
(1/4-1/3)<0 所以|1/4-1/3|=1/3-1/4
(1/5-1/4)<0 所以|1/5-1/4|=1/4-1/5
...
(1/2007-1/2006)>0 所以 |1/2007-1/2006|=1/2006-1-2007
那么原式就可以表示为
(1/2-1/3)+(1/3-1/4)+(1/4-1/5)+...+(1/2006-1/2007)
=1/2-1/3+1/3-1/4+1/4+...-1/2006+1/2006-1/2007
=1/2-1/2007
=2005/4014
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